Pea Pea, n.; pl. {Peas}or {Pease}. [OE. pese, fr. AS. pisa, or
OF. peis, F. pois; both fr. L. pisum; cf. Gr. ?, ?. The final
s was misunderstood in English as a plural ending. Cf.
{Pease}.]
1. (Bot.) A plant, and its fruit, of the genus {Pisum}, of
many varieties, much cultivated for food. It has a
papilionaceous flower, and the pericarp is a legume,
popularly called a pod.
[1913 Webster]

Note: When a definite number, more than one, is spoken of,
the plural form peas is used; as, the pod contained
nine peas; but, in a collective sense, the form pease
is preferred; as, a bushel of pease; they had pease at
dinner. This distinction is not always preserved, the
form peas being used in both senses.
[1913 Webster]